Electric current impulse transmitter



Sept. 6,1953 0. MQSER I 2,651,676

ELECTRIC CURRENT IMPULSE TRANSMITTER Filed Aug. 14, 1951 a -2.9 2] l/dINYENTOR I 0270 [106672 B) c. M

ATTORNEY Patented Sept. 8, 1953 UNITED ELECTRIC CURRENT IMPULSETRANSMITTER Otto lVIoser, Bern Switzerland Application August 14, 1951,Serial No. 241,758 In Switzerland August 24, 1950 6 Claims.

This invention relates to the transmitting of electric current impulsesand more especially of combinations of such current impulses as are usedin the operation of telegraph apparatus, telautographs, telewriters andthe like.

The invention is especially concerned with transmitting devices whichconvert the signal or the like into current impulse combinations.Devices of the kind aforesaid as hitherto known comprise a settingmechanism, i. e. a keyboard with a number of individual keys or a dialfor the combinations of current impulses to be transmitted, furthercertain controlling elements operatively connected with the settingdevice, for instance impulse discs keyed on a common shaft or ondifferent shafts, means for driving this shaft or shafts and a contactdevice controlled by the control elements for transmitting thecombinations of current impulses.

In the known devices of this kind. in which impulse discs are used ascontrolling elements, these discs are formed with projecting cams. Incontrast to these devices, the impulse discs forming part of thetransmitting devices-according to the present invention have on one oftheir disc surfaces a cam groove which extends around the disc axis andis characteristic of one particular combination of current impulses.When the setting mechanism is operated, a pin, finger or other feelercooperating with the disc enters the cam groove and is thereafter movedaccording to the configuration of the groove to control the contactdevice and provide for transmission of the combination of currentimpulses corresponding to the adjustment of the setting device such asfor instance the individual key which had been depressed.

In the drawings affixed to this specification and forming part thereof,an embodiment of the invention is illustrated diagrammatically by way ofexample.

In the drawings:

Fig. 1 is a schematic showing, in perspective, of the mechanical part ofthe device, while Fig. 2 is a schematic showing of the electrical partand wirin diagram.

Fig. 3 is a plan view, drawn to a larger of an impulse disc.

Referring to the drawings, in Figs. 1 and 2 denotes one of theselectively operable key bars of the keyboard mechanism. For the sake ofsimplicity only one such bar and key are shown. A snap switch I lcapable of assuming two different positions controls the starting of adriving device 12 servingto drive a shaft l3. Keyed on scale,

cam disc l5 and a working cam disc l6.

the shaft are pulse control discs [4, one for each key bar. Each disc I4has a cam groove 2'1. Firmly mounted on shaft 13 are further a rest- Adelaying disc I! is mounted loosely on the shaft I3.

The key bars l5 have the form of double-armed levers fixedon an axle l8supported for rocking motion. One arm of these levers carries the keyhead l9 and'a vertical arm 20, while the other arm 2| of th lever servesfor actuating the start switch II. A tension spring 22 tends to maintainthe key ill in its position of rest. A bar 24 having a pin or feeler 25to be controlled by the cam groove 21. Bar 24 has the form of adoublearmed lever and is mounted for rocking movement on an axle 23 andforced by a coil spring 25 with one of its arms against the arm 20 ofthe key bar I0. Arm 24 also carries the pin 26 which, when key I0 isbeing depressed, enters through an opening at the periphery of disc I4into the cam groove 21 of disc l4.

A contact device 29 serving for transmitting the current impulsecombinations is actuated by arm 28 of bar 24 in accordance with theconfiguration of the cam groove 21. The cam disc [5 carries a finger3i], and a disc l'i loose on shaft 13 carries a pin 3!. In the positionof rest of the mechanism, pin 3| is angularly spaced from finger 30 sothatfinger 30 comes into contact with pin" 3| only after the disc l5 hasgone through a predetermined angular movement, to then carry along thedisc I1. The disc l5, by means of its cam 38, can operate a rest contactk. The discs 16 and I! are coupled with respective working contact s andv (Fig. 2.)

The driving device 12 as'here provided is of an electromagnetic kindcomprising fixed electromagnets 32 and 33 which are excited inpairwisealternation through self-controlled contacts m32 andm3-3, respectively.The driving device further comprises a rotor (not shown) with definitepoles. The driving devices as here described are particularly welladapted for the purpose here in View for the reason that they can bebrought to a standstill instantaneously in a simple man-' n'e'r bymagnetic action as will be explained more in 'detail hereinafter. cuits34 and 35 are connected across respective contacts'm32 and 17233. Thedriving device 12 iss'upplied with current from a line 35 which may suply a -vo1t'direct'currentp The transmitter-here above described operatesas follows:

Spark extinguishing cir-' On a key It] being depressed, the vertical arm20 of the key bar exerts pressure on one arm of the pin carrier 24,whereby the pin 26 is caused to enter the cam groove 21 of thepertaining impulse disc l1. Simultaneously the arm 2i of the key lactuates the switch II whereby the circuit for the driving device 12 isclosed. The current flows from line 36 by way of the closed switchconacts lib, contact *m32, through the windings of the electromagnets 32back to the line. Owing to the excitation of the electromagnets 32 therotor (not shown) is started rotating and by means of the gearing 3'1sets the shaft i3 revolving. Now the contacts m32 and m33 are opened andclosed alternate1y, whereby the electromagnets 32 and 33 are excitedalterhating-1y. In accordance with the configuration of the cam groove21 of the impulse disc M the arm 28 will now actuate the switch 29 whichtransmits the current impulses into the wire 39. On the key l0 beingreleased, the contacts H-b are opened and the contacts Ha areclosedagain. In the meantime the loosely seated disc 17 has turnedthrough an angle such that the pertaining holding contact 12 is closedand the driving device i2 is now supplied with current through thecontact 1). Shortly before the end of a full revolution the cam of thedisc it closes the contact s. Apart from this, directly after the shaft33 has started revolving, the contact 7c is opened. After a completerevolution the cam 38 of disc l closes again the contact is. This leadsto a bridging of the contacts 12132 and m33 whereby both pairs ofelectromagnets 32 and 33 are excited simultaneously and the drivingdevice 1-2 is instantly brought to a standstill.

In order to prevent the braking period from beingtoo short, theinterruption of the current supply to the driving device 12 by contact2) is delayed a short period of time after the shaft 13 is arrested.This delay is due to the fact that, when shaft i3 is suddenly arrested,the disc 11 which is loose on this shaft continues revolving under itsown momentum. Only after the disc H has returned into its position ofrest is contact 1; opened so that now the entire device is in itsinitial position.

Ihe working cam disc It guarantees the stopping of the driving device 12after completion of one revolution independently of the position of thekey it and regardless of whether key fl-0 remains in its depressedposition or is released at once. Directly before the shaft 13 hascompleted its revolution, the contact s is closed by the cam M of thedisc 16 whereby any contacts Ha which may still be open are bridgedalso.

The pulse control disc l4 illustrated by way of example in Fig. 3 isdesigned for use in connection with a device operating as a transmittorfor a telegraph system working in accordance with the 5-current stepalphabet. To this end the impulse disc is subdivided .into sevensections, namely a section I which may be called the blocking step, asection 2 representing the starting step for the transmitter and fivefurther sections which represent the current impulse combination propercorresponding to the signals to be transmitted. The particular shape ofthe cam slot is chosen in accordance with the one signal to betransmitted by each cam disc M. The slot sections corresponding to theblocking and starting steps are of uniform configuration in all impulsediscs belonging to the device.

As compared with known devices of similar type comprising discs withprojecting cams as control elements for the transmission of theimpulses, the cam slot discs offer the advantage of guaranteeing, by thepositive steering of the pin or finger in the individually formed camslots of the impulse discs, a far safer working of the device, becauseit does away with the bouncing and wear of contacts which frequentlyoccur in devices operatin with projecting cam discs. Impulse distortionsare practically rendered impossible, so that the transmitter cannottransmit any faulty combinations of current impulses and consequentlyany wrong signals.

A further advantage offered by the mechanism Ihereabove described ascompared with transmitters comprising setting members common todifferent impulse combinations consists in that any setting element, forinstance an impulse disc which might become defective during theoperation, will disturb only 'a single combination of current impulses,while in the old devices all combinations controlled by a common settingmember are disturbed.

I wish it to be understood that I do not desire to be limited to theexact details described in the foregoin specification and shown in thedrawings for obvious modifications will occur to a person skilled in theart.

This invention is related to that of my copending application Serial No.260,522, filed December 1, 1951, new Patent No. 2,612,556.

I claim:

1. Apparatus for transmitting electric pulse combinations, comprising amechanism for selecting a pulse combination to be transmitted, a

shaft, 3, drive joined with said shaft, a pulse control disc for each ofthe available pulse combinaations mounted on said shaft to revolvetogether therewith, a start switch controlled by said mechanism andconnected with said drive for starting said drive when said mechanism isactuated, pulse contact means for transmitting said pulse combinationhaving a movable contact control member with a feeler, said pulsecontrol disc having a cam groove extending around said shaft and havinga composite curve shape corresponding to one of said pulse combinations,said movable control member and feeler having a bias away from saidgroove, and said mechanism, when being actuated to control said startswitch, being engageable with said control member to move said feeleragainst said bias into said groove, and said groove having a crosssectional shape straddling said feeler and forming a double-sidedguiding contour for oscillating said feeler.

.2. Apparatus for transmitting electric pulse combinations, comprising apulse control disc for each of the respective pulse combinations, ashaft having a one-revolution drive joined therewith, said disc beingfirmly mounted on said shaft to revolve together therewith, said dischaving a lateral cam groove closed upon itself around said shaft andhaving a composite curve shape corresponding to one of the pulsecombinations, and said disc having a passage extending from said grooveto the disc periphery and located at a given place when said drive is atrest, pulse contact means for transmitting said pulse combination havinga movable contact con trol member with a feeler disposed near said discat said place and biased away from said disc, a pulse-combination.selector mechanism, a start switch controlled by said mechanism andconnected with said drive for starting :said drive when said mechanismis actuated, said mechanism when actuated being in engagement with saidcontact control member to move said feeler through said passage intosaid groove, and said g'roove having a cross sectional shape straddlingsaid feeler to hold it oscillatorily engaged in said groove duringrevolution of said disc.

3. In pulse transmitting apparatus according to claim 2, said groovehaving a first curve section for issuing a receiver-releasin pulse aheadof the pulse combination, said first curve section beginning a givenangular amount from the rest position of said feeler so that thereleasing pulse is issued only after said pulse control disc has gonethrough a given part of its revolution, said first curve section beingfollowed by said composite curve shape corresponding to the pulsecombination proper.

4. Apparatus for transmitting electric pulse combinations, comprising amechanism for selecting a pulse combination to be transmitted, a shaft,a drive motor joined with said shaft and having a motor control circuit,said circuit comprising a normally open start switch and a normally openholding contact parallel connected to said start switch, a pulse controlmember firmly mounted on said shaft to revolve together therewith,electric pulse contact means disposed for transmitting said pulsecombination and engageable with said member to be actuated by revolutionof said member, said start switch being engageable by said mechanism forclosing said circuit to start said drive motor when said mechanism isactuated, a cam disc loosely seated on said shaft and engageable withsaid holding contact to close said holding contact only when moved outof a given rest position, stop means firmly secured to said shaft andengageable with said cam disc after a given angle of revolution of saidshaft to then entrain said cam disc, whereby said cam disc closes saidholding contact to maintain said motor running independently of saidstart switch.

5. Apparatus for transmitting electric pulse combinations, comprising amechanism for selecting a pulse combination to be transmitted, a shaft,a drive motor joined with said shaft and having a motor energizing saidcircuit and a braking circuit, said energizing circuit comprising anormally open start switch and a normally open holding contact parallelto said start switch, and said braking circuit comprising a stop controlcontact, a pulse control member firmly mounted onsaid shaft to revolvetogether therewith, electric. pulse contact means disposed for transmitting said pulse combination and engageable with said member to beactuated by revolution of said member, said start switch beingengageable by said mechanism for closing said energizing circuit tostart said motor when said mechanism is actuated, a first cam discloosely seated on said shaft and engageable with said holding contact toclose said holding contact only when moved out of a given rest position,a second cam disc firmly mounted on said shaft and having a partabuttable against said first cam disc but angularly spaced therefrom soas to entrain said first cam disc for revolution from said rest positionwhen said second cam disc has passed through a given portion of itsrevolution, said second cam disc being engageable with said stop controlcontact at the end of said revolution to arrest said motor.

6. In pulse transmitting apparatus according to claim 5, said second camdisc having a continuous cam contour in contact-closing engagemerit withsaid holding contact over the entire cam periphery with the exception ofa peripheral cam portion located at said holding contact when saidsecond cam disc is in said rest position, and said second cam dischaving a, mass sufiicient for said second cam disc to continue movingunder its own momentum after said first cam disc has completed itsrevolution, whereby said second cam disc opens said holding contact toreset the apparatus for renewed operation of said mechanism a givenperiod of time after completion of the pulse transmission.

